cloneDeep.js 1.84 KB
define(['../internal/baseClone', '../internal/bindCallback'], function(baseClone, bindCallback) {

  /**
   * Creates a deep clone of `value`. If `customizer` is provided it's invoked
   * to produce the cloned values. If `customizer` returns `undefined` cloning
   * is handled by the method instead. The `customizer` is bound to `thisArg`
   * and invoked with up to three argument; (value [, index|key, object]).
   *
   * **Note:** This method is loosely based on the
   * [structured clone algorithm](http://www.w3.org/TR/html5/infrastructure.html#internal-structured-cloning-algorithm).
   * The enumerable properties of `arguments` objects and objects created by
   * constructors other than `Object` are cloned to plain `Object` objects. An
   * empty object is returned for uncloneable values such as functions, DOM nodes,
   * Maps, Sets, and WeakMaps.
   *
   * @static
   * @memberOf _
   * @category Lang
   * @param {*} value The value to deep clone.
   * @param {Function} [customizer] The function to customize cloning values.
   * @param {*} [thisArg] The `this` binding of `customizer`.
   * @returns {*} Returns the deep cloned value.
   * @example
   *
   * var users = [
   *   { 'user': 'barney' },
   *   { 'user': 'fred' }
   * ];
   *
   * var deep = _.cloneDeep(users);
   * deep[0] === users[0];
   * // => false
   *
   * // using a customizer callback
   * var el = _.cloneDeep(document.body, function(value) {
   *   if (_.isElement(value)) {
   *     return value.cloneNode(true);
   *   }
   * });
   *
   * el === document.body
   * // => false
   * el.nodeName
   * // => BODY
   * el.childNodes.length;
   * // => 20
   */
  function cloneDeep(value, customizer, thisArg) {
    return typeof customizer == 'function'
      ? baseClone(value, true, bindCallback(customizer, thisArg, 3))
      : baseClone(value, true);
  }

  return cloneDeep;
});